© Faculty of Mechanical Engineering, Belgrade. All rights reserved FME Transactions (2020) 48, 391-396 391 Received: January 2019, Accepted: December 2019 Correspondence to: Dr N.Ethiraj, Dr. M.G.R Educational and Research Institute, Department of Mechanical Engineering, Tamilnadu, India. E-mail: ethiraj.mech@drmgrdu.ac.in doi:10.5937/fme2002391K Suresh Kumar D Research Scholar Dr.M.G.R Educational and Research Institute, Tamilnadu India Ethiraj N Professor Dr.M.G.R Educational and Research Institute, Tamilnadu India Sivabalan T Assistant Professor Dr.M.G.R Educational and Research Institute, Tamilnadu India Mohamed Farhan M R UG Student Dr.M.G.R Educational and Research Institute, Tamilnadu India Bernadette T UG Student Dr.M.G.R Educational and Research Institute, Tamilnadu India Investigation on Component Wall Angle in Single Stage Incremental Forming of Austenitic Stainless Steel AISI 304 Sheet The aim of this research work is to study the effect of process parameters in achieving the maximum possible wall angle of the component in single stage incremental forming. Austenitic stainless steel AISI 304 is used as a sheet material. The constant tool rotational speed of 250 rpm, tool feed of 1000 mm/min and incremental depth of 0.5 mm were used as process parameters and the wall angle was varied from 60 o .Grid marking technique is used for strain measurements. From the results, it is observed that the maximum height of 45 mm was formed successfully at wall angles 60 o , 61 o , 63 o and 64 o without any defects within the experimented process parameters. Further increase in either the wall angle or the process parameters produced fractured component at a height of around 22 mm itself. Keywords: Single Stage Incremental Forming, Austenitic Stainless Steel, Wall angle, Tool Rotational Speed, Incremental depth 1. INTRODUCTION Incremental forming is one of the non-traditional forming processes used for developing a prototype of a component. It is also known as die-less forming in which the rotating tool follow the contour of the com- ponent to be produced and incremented by a step size to reach the required depth which is controlled by the Computer Numerically Controlled machine(CNC) prog- ramming. It finds applications in rapid prototyping of components used in automobile, aeronautics, medical and aerospace industries. Recently, the custom made medical implants like Maxillofacial [1], orthopaedics are manufactured by Fused deposition modeling (FDM), Multi-jet 3D printing and 3D printing [2] respectively. Similar implants can be manufactured using the incre- mental forming process due to the flexibility to the de- sign changes according to the patient’s need. Inves- tigation on incremental forming in different materials like steel [3-5], magnesium alloy [6], aluminium alloy [7-9], titanium [10,11], stainless steel [12-18], polymer [19] etc. have been carried out by many researchers in the past. Information regarding incremental forming of aluminium and magnesium are exhaustive whereas for other materials, it is very limited. Subramanian Chez- hian Babu and Velukkudy Santhanam SenthilKumar [14] have performed forming of conical shaped com- ponent with wall angle approximately 50 o and part depth of 30mm using 0.6mm thick stainless steel sheet. Highest forming limit was achieved at a feed of 1600 mm/min and tool rotational speed of 1000rpm. Sa'id Golabi and Hossain Khazaali [16] have investigated the effect of wall angle on the achieved depth of the component in 0.3-1 mm stainless steel 304 sheet. It was concluded from the result that the maximum depth achi- eved was 20mm when the wall angle is 64 o , whereas, it is only14.5 mm approximately at 84 o in single stage incremental forming. Giuseppe Ingarao et al. [17] have successfully reached the depth of 40mm at a wall angle of 45 o in 0.8mm thick stainless steel sheet. Also they documented the energy demand during incremental forming and concluded that the dominant factor in deciding the energy required is the forming time among the process parameters considered. In order to improve the wall angle more than what is attainable in single stage, incremental forming in mul- tistages was attempted by few researchers. Mohammad Javad Mirnia et al. [20] explained that, in 1mm thick aluminium alloy sheet, the formation of truncated cone with wall angle of 60 o for a height of approximately 15 mm was made without any fracture in two stage for- ming. Li Jun-chao et al. [21] worked on DC06 Steel with 0.8mm thick using three stage forming at a wall angle of 30 o . It was concluded that the final thickness value was more than the value predicted by sine law and hence cannot be applied to multistage forming. A novel study on tooling [22,23] was done by Tyler J Grimm et al. They proposed multidirectional tooling and achieved 23% improvement in formability when compared with single tool forming. Furthermore, few researchers have attempted a hybrid forming [24-28] by combining superplastic, laser, elec- tromagnetic, ultrasonic and friction stir incremental form- ing to improve the formability. Rubber pad forming is used for fabricating the components for aircraft industry due to the advantage that the parts with different dimen-